text: // SPDX-License-Identifier: GPL-2.0+
  /*
   * Copyright (c) 2016-2018, NVIDIA CORPORATION.
   */
  
  #include <common.h>
  #include <environment.h>
  #include <fdt_support.h>
  #include <fdtdec.h>
  #include <stdlib.h>
  #include <string.h>
  
  #include <linux/ctype.h>
  #include <linux/sizes.h>
  
  #include <asm/arch/tegra.h>
  #include <asm/arch-tegra/cboot.h>
  #include <asm/armv8/mmu.h>
  
  /*
   * Size of a region that's large enough to hold the relocated U-Boot and all
   * other allocations made around it (stack, heap, page tables, etc.)
   * In practice, running "bdinfo" at the shell prompt, the stack reaches about
   * 5MB from the address selected for ram_top as of the time of writing,
   * so a 16MB region should be plenty.
   */
  #define MIN_USABLE_RAM_SIZE SZ_16M
  /*
   * The amount of space we expect to require for stack usage. Used to validate
   * that all reservations fit into the region selected for the relocation target
   */
  #define MIN_USABLE_STACK_SIZE SZ_1M
  
  DECLARE_GLOBAL_DATA_PTR;
  
  extern struct mm_region tegra_mem_map[];
  
  /*
   * These variables are written to before relocation, and hence cannot be
   * in.bss, since .bss overlaps the DTB that's appended to the U-Boot binary.
   * The section attribute forces this into .data and avoids this issue. This
   * also has the nice side-effect of the content being valid after relocation.
   */
  
  /* The number of valid entries in ram_banks[] */
  static int ram_bank_count __attribute__((section(".data")));
  
  /*
   * The usable top-of-RAM for U-Boot. This is both:
   * a) Below 4GB to avoid issues with peripherals that use 32-bit addressing.
   * b) At the end of a region that has enough space to hold the relocated U-Boot
   *    and all other allocations made around it (stack, heap, page tables, etc.)
   */
  static u64 ram_top __attribute__((section(".data")));
  /* The base address of the region of RAM that ends at ram_top */
  static u64 region_base __attribute__((section(".data")));
  
  /*
   * Explicitly put this in the .data section because it is written before the
   * .bss section is zeroed out but it needs to persist.
   */
  unsigned long cboot_boot_x0 __attribute__((section(".data")));
  
  void cboot_save_boot_params(unsigned long x0, unsigned long x1,
  			    unsigned long x2, unsigned long x3)
  {
  	cboot_boot_x0 = x0;
  }
  
  int cboot_dram_init(void)
  {
  	unsigned int na, ns;
  	const void *cboot_blob = (void *)cboot_boot_x0;
  	int node, len, i;
  	const u32 *prop;
  
  	if (!cboot_blob)
  		return -EINVAL;
  
  	na = fdtdec_get_uint(cboot_blob, 0, "#address-cells", 2);
  	ns = fdtdec_get_uint(cboot_blob, 0, "#size-cells", 2);
  
  	node = fdt_path_offset(cboot_blob, "/memory");
  	if (node < 0) {
  		pr_err("Can't find /memory node in cboot DTB");
  		hang();
  	}
  	prop = fdt_getprop(cboot_blob, node, "reg", &len);
  	if (!prop) {
  		pr_err("Can't find /memory/reg property in cboot DTB");
  		hang();
  	}
  
  	/* Calculate the true # of base/size pairs to read */
  	len /= 4;		/* Convert bytes to number of cells */
  	len /= (na + ns);	/* Convert cells to number of banks */
  	if (len > CONFIG_NR_DRAM_BANKS)
  		len = CONFIG_NR_DRAM_BANKS;
  
  	/* Parse the /memory node, and save useful entries */
  	gd->ram_size = 0;
  	ram_bank_count = 0;
  	for (i = 0; i < len; i++) {
  		u64 bank_start, bank_end, bank_size, usable_bank_size;
  
  		/* Extract raw memory region data from DTB */
  		bank_start = fdt_read_number(prop, na);
  		prop += na;
  		bank_size = fdt_read_number(prop, ns);
  		prop += ns;
  		gd->ram_size += bank_size;
  		bank_end = bank_start + bank_size;
  		debug("Bank %d: %llx..%llx (+%llx)\n", i,
  		      bank_start, bank_end, bank_size);
  
  		/*
  		 * Align the bank to MMU section size. This is not strictly
  		 * necessary, since the translation table construction code
  		 * handles page granularity without issue. However, aligning
  		 * the MMU entries reduces the size and number of levels in the
  		 * page table, so is worth it.
  		 */
  		bank_start = ROUND(bank_start, SZ_2M);
  		bank_end = bank_end & ~(SZ_2M - 1);
  		bank_size = bank_end - bank_start;
  		debug("  aligned: %llx..%llx (+%llx)\n",
  		      bank_start, bank_end, bank_size);
  		if (bank_end <= bank_start)
  			continue;
  
  		/* Record data used to create MMU translation tables */
  		ram_bank_count++;
  		/* Index below is deliberately 1-based to skip MMIO entry */
  		tegra_mem_map[ram_bank_count].virt = bank_start;
  		tegra_mem_map[ram_bank_count].phys = bank_start;
  		tegra_mem_map[ram_bank_count].size = bank_size;
  		tegra_mem_map[ram_bank_count].attrs =
  			PTE_BLOCK_MEMTYPE(MT_NORMAL) | PTE_BLOCK_INNER_SHARE;
  
  		/* Determine best bank to relocate U-Boot into */
  		if (bank_end > SZ_4G)
  			bank_end = SZ_4G;
  		debug("  end  %llx (usable)\n", bank_end);
  		usable_bank_size = bank_end - bank_start;
  		debug("  size %llx (usable)\n", usable_bank_size);
  		if ((usable_bank_size >= MIN_USABLE_RAM_SIZE) &&
  		    (bank_end > ram_top)) {
  			ram_top = bank_end;
  			region_base = bank_start;
  			debug("ram top now %llx\n", ram_top);
  		}
  	}
  
  	/* Ensure memory map contains the desired sentinel entry */
  	tegra_mem_map[ram_bank_count + 1].virt = 0;
  	tegra_mem_map[ram_bank_count + 1].phys = 0;
  	tegra_mem_map[ram_bank_count + 1].size = 0;
  	tegra_mem_map[ram_bank_count + 1].attrs = 0;
  
  	/* Error out if a relocation target couldn't be found */
  	if (!ram_top) {
  		pr_err("Can't find a usable RAM top");
  		hang();
  	}
  
  	return 0;
  }
  
  int cboot_dram_init_banksize(void)
  {
  	int i;
  
  	if (ram_bank_count == 0)
  		return -EINVAL;
  
  	if ((gd->start_addr_sp - region_base) < MIN_USABLE_STACK_SIZE) {
  		pr_err("Reservations exceed chosen region size");
  		hang();
  	}
  
  	for (i = 0; i < ram_bank_count; i++) {
  		gd->bd->bi_dram[i].start = tegra_mem_map[1 + i].virt;
  		gd->bd->bi_dram[i].size = tegra_mem_map[1 + i].size;
  	}
  
  #ifdef CONFIG_PCI
  	gd->pci_ram_top = ram_top;
  #endif
  
  	return 0;
  }
  
  ulong cboot_get_usable_ram_top(ulong total_size)
  {
  	return ram_top;
  }
  
  /*
   * The following few functions run late during the boot process and dynamically
   * calculate the load address of various binaries. To keep track of multiple
   * allocations, some writable list of RAM banks must be used. tegra_mem_map[]
   * is used for this purpose to avoid making yet another copy of the list of RAM
   * banks. This is safe because tegra_mem_map[] is only used once during very
   * early boot to create U-Boot's page tables, long before this code runs. If
   * this assumption becomes invalid later, we can just fix the code to copy the
   * list of RAM banks into some private data structure before running.
   */
  
  static char *gen_varname(const char *var, const char *ext)
  {
  	size_t len_var = strlen(var);
  	size_t len_ext = strlen(ext);
  	size_t len = len_var + len_ext + 1;
  	char *varext = malloc(len);
  
  	if (!varext)
  		return 0;
  	strcpy(varext, var);
  	strcpy(varext + len_var, ext);
  	return varext;
  }
  
  static void mark_ram_allocated(int bank, u64 allocated_start, u64 allocated_end)
  {
  	u64 bank_start = tegra_mem_map[bank].virt;
  	u64 bank_size = tegra_mem_map[bank].size;
  	u64 bank_end = bank_start + bank_size;
  	bool keep_front = allocated_start != bank_start;
  	bool keep_tail = allocated_end != bank_end;
  
  	if (keep_front && keep_tail) {
  		/*
  		 * There are CONFIG_NR_DRAM_BANKS DRAM entries in the array,
  		 * starting at index 1 (index 0 is MMIO). So, we are at DRAM
  		 * entry "bank" not "bank - 1" as for a typical 0-base array.
  		 * The number of remaining DRAM entries is therefore
  		 * "CONFIG_NR_DRAM_BANKS - bank". We want to duplicate the
  		 * current entry and shift up the remaining entries, dropping
  		 * the last one. Thus, we must copy one fewer entry than the
  		 * number remaining.
  		 */
  		memmove(&tegra_mem_map[bank + 1], &tegra_mem_map[bank],
  			CONFIG_NR_DRAM_BANKS - bank - 1);
  		tegra_mem_map[bank].size = allocated_start - bank_start;
  		bank++;
  		tegra_mem_map[bank].virt = allocated_end;
  		tegra_mem_map[bank].phys = allocated_end;
  		tegra_mem_map[bank].size = bank_end - allocated_end;
  	} else if (keep_front) {
  		tegra_mem_map[bank].size = allocated_start - bank_start;
  	} else if (keep_tail) {
  		tegra_mem_map[bank].virt = allocated_end;
  		tegra_mem_map[bank].phys = allocated_end;
  		tegra_mem_map[bank].size = bank_end - allocated_end;
  	} else {
  		/*
  		 * We could move all subsequent banks down in the array but
  		 * that's not necessary for subsequent allocations to work, so
  		 * we skip doing so.
  		 */
  		tegra_mem_map[bank].size = 0;
  	}
  }
  
  static void reserve_ram(u64 start, u64 size)
  {
  	int bank;
  	u64 end = start + size;
  
  	for (bank = 1; bank <= CONFIG_NR_DRAM_BANKS; bank++) {
  		u64 bank_start = tegra_mem_map[bank].virt;
  		u64 bank_size = tegra_mem_map[bank].size;
  		u64 bank_end = bank_start + bank_size;
  
  		if (end <= bank_start || start > bank_end)
  			continue;
  		mark_ram_allocated(bank, start, end);
  		break;
  	}
  }
  
  static u64 alloc_ram(u64 size, u64 align, u64 offset)
  {
  	int bank;
  
  	for (bank = 1; bank <= CONFIG_NR_DRAM_BANKS; bank++) {
  		u64 bank_start = tegra_mem_map[bank].virt;
  		u64 bank_size = tegra_mem_map[bank].size;
  		u64 bank_end = bank_start + bank_size;
  		u64 allocated = ROUND(bank_start, align) + offset;
  		u64 allocated_end = allocated + size;
  
  		if (allocated_end > bank_end)
  			continue;
  		mark_ram_allocated(bank, allocated, allocated_end);
  		return allocated;
  	}
  	return 0;
  }
  
  static void set_calculated_aliases(char *aliases, u64 address)
  {
  	char *tmp, *alias;
  	int err;
  
  	aliases = strdup(aliases);
  	if (!aliases) {
  		pr_err("strdup(aliases) failed");
  		return;
  	}
  
  	tmp = aliases;
  	while (true) {
  		alias = strsep(&tmp, " ");
  		if (!alias)
  			break;
  		debug("%s: alias: %s\n", __func__, alias);
  		err = env_set_hex(alias, address);
  		if (err)
  			pr_err("Could not set %s\n", alias);
  	}
  
  	free(aliases);
  }
  
  static void set_calculated_env_var(const char *var)
  {
  	char *var_size;
  	char *var_align;
  	char *var_offset;
  	char *var_aliases;
  	u64 size;
  	u64 align;
  	u64 offset;
  	char *aliases;
  	u64 address;
  	int err;
  
  	var_size = gen_varname(var, "_size");
  	if (!var_size)
  		return;
  	var_align = gen_varname(var, "_align");
  	if (!var_align)
  		goto out_free_var_size;
  	var_offset = gen_varname(var, "_offset");
  	if (!var_offset)
  		goto out_free_var_align;
  	var_aliases = gen_varname(var, "_aliases");
  	if (!var_aliases)
  		goto out_free_var_offset;
  
  	size = env_get_hex(var_size, 0);
  	if (!size) {
  		pr_err("%s not set or zero\n", var_size);
  		goto out_free_var_aliases;
  	}
  	align = env_get_hex(var_align, 1);
  	/* Handle extant variables, but with a value of 0 */
  	if (!align)
  		align = 1;
  	offset = env_get_hex(var_offset, 0);
  	aliases = env_get(var_aliases);
  
  	debug("%s: Calc var %s; size=%llx, align=%llx, offset=%llx\n",
  	      __func__, var, size, align, offset);
  	if (aliases)
  		debug("%s: Aliases: %s\n", __func__, aliases);
  
  	address = alloc_ram(size, align, offset);
  	if (!address) {
  		pr_err("Could not allocate %s\n", var);
  		goto out_free_var_aliases;
  	}
  	debug("%s: Address %llx\n", __func__, address);
  
  	err = env_set_hex(var, address);
  	if (err)
  		pr_err("Could not set %s\n", var);
  	if (aliases)
  		set_calculated_aliases(aliases, address);
  
  out_free_var_aliases:
  	free(var_aliases);
  out_free_var_offset:
  	free(var_offset);
  out_free_var_align:
  	free(var_align);
  out_free_var_size:
  	free(var_size);
  }
  
  #ifdef DEBUG
  static void dump_ram_banks(void)
  {
  	int bank;
  
  	for (bank = 1; bank <= CONFIG_NR_DRAM_BANKS; bank++) {
  		u64 bank_start = tegra_mem_map[bank].virt;
  		u64 bank_size = tegra_mem_map[bank].size;
  		u64 bank_end = bank_start + bank_size;
  
  		if (!bank_size)
  			continue;
  		printf("%d: %010llx..%010llx (+%010llx)\n", bank - 1,
  		       bank_start, bank_end, bank_size);
  	}
  }
  #endif
  
  static void set_calculated_env_vars(void)
  {
  	char *vars, *tmp, *var;
  
  #ifdef DEBUG
  	printf("RAM banks before any calculated env. var.s:\n");
  	dump_ram_banks();
  #endif
  
  	reserve_ram(cboot_boot_x0, fdt_totalsize(cboot_boot_x0));
  
  #ifdef DEBUG
  	printf("RAM after reserving cboot DTB:\n");
  	dump_ram_banks();
  #endif
  
  	vars = env_get("calculated_vars");
  	if (!vars) {
  		debug("%s: No env var calculated_vars\n", __func__);
  		return;
  	}
  
  	vars = strdup(vars);
  	if (!vars) {
  		pr_err("strdup(calculated_vars) failed");
  		return;
  	}
  
  	tmp = vars;
  	while (true) {
  		var = strsep(&tmp, " ");
  		if (!var)
  			break;
  		debug("%s: var: %s\n", __func__, var);
  		set_calculated_env_var(var);
  #ifdef DEBUG
  		printf("RAM banks after allocating %s:\n", var);
  		dump_ram_banks();
  #endif
  	}
  
  	free(vars);
  }
  
  static int set_fdt_addr(void)
  {
  	int ret;
  
  	ret = env_set_hex("fdt_addr", cboot_boot_x0);
  	if (ret) {
  		printf("Failed to set fdt_addr to point at DTB: %d\n", ret);
  		return ret;
  	}
  
  	return 0;
  }
  
  /*
   * Attempt to use /chosen/nvidia,ether-mac in the cboot DTB to U-Boot's
   * ethaddr environment variable if possible.
   */
  static int cboot_get_ethaddr_legacy(const void *fdt, uint8_t mac[ETH_ALEN])
  {
  	const char *const properties[] = {
  		"nvidia,ethernet-mac",
  		"nvidia,ether-mac",
  	};
  	const char *prop;
  	unsigned int i;
  	int node, len;
  
  	node = fdt_path_offset(fdt, "/chosen");
  	if (node < 0) {
  		printf("Can't find /chosen node in cboot DTB\n");
  		return node;
  	}
  
  	for (i = 0; i < ARRAY_SIZE(properties); i++) {
  		prop = fdt_getprop(fdt, node, properties[i], &len);
  		if (prop)
  			break;
  	}
  
  	if (!prop) {
  		printf("Can't find Ethernet MAC address in cboot DTB\n");
  		return -ENOENT;
  	}
  
  	eth_parse_enetaddr(prop, mac);
  
  	if (!is_valid_ethaddr(mac)) {
  		printf("Invalid MAC address: %s\n", prop);
  		return -EINVAL;
  	}
  
  	debug("Legacy MAC address: %pM\n", mac);
  
  	return 0;
  }
  
  int cboot_get_ethaddr(const void *fdt, uint8_t mac[ETH_ALEN])
  {
  	int node, len, err = 0;
  	const uchar *prop;
  	const char *path;
  
  	path = fdt_get_alias(fdt, "ethernet");
  	if (!path) {
  		err = -ENOENT;
  		goto out;
  	}
  
  	debug("ethernet alias found: %s\n", path);
  
  	node = fdt_path_offset(fdt, path);
  	if (node < 0) {
  		err = -ENOENT;
  		goto out;
  	}
  
  	prop = fdt_getprop(fdt, node, "local-mac-address", &len);
  	if (!prop) {
  		err = -ENOENT;
  		goto out;
  	}
  
  	if (len != ETH_ALEN) {
  		err = -EINVAL;
  		goto out;
  	}
  
  	debug("MAC address: %pM\n", prop);
  	memcpy(mac, prop, ETH_ALEN);
  
  out:
  	if (err < 0)
  		err = cboot_get_ethaddr_legacy(fdt, mac);
  
  	return err;
  }
  
  static char *strip(const char *ptr)
  {
  	const char *end;
  
  	while (*ptr && isblank(*ptr))
  		ptr++;
  
  	/* empty string */
  	if (*ptr == '\0')
  		return strdup(ptr);
  
  	end = ptr;
  
  	while (end[1])
  		end++;
  
  	while (isblank(*end))
  		end--;
  
  	return strndup(ptr, end - ptr + 1);
  }
  
  static char *cboot_get_bootargs(const void *fdt)
  {
  	const char *args;
  	int offset, len;
  
  	offset = fdt_path_offset(fdt, "/chosen");
  	if (offset < 0)
  		return NULL;
  
  	args = fdt_getprop(fdt, offset, "bootargs", &len);
  	if (!args)
  		return NULL;
  
  	return strip(args);
  }
  
  int cboot_late_init(void)
  {
  	const void *fdt = (const void *)cboot_boot_x0;
  	uint8_t mac[ETH_ALEN];
  	char *bootargs;
  	int err;
  
  	set_calculated_env_vars();
  	/*
  	 * Ignore errors here; the value may not be used depending on
  	 * extlinux.conf or boot script content.
  	 */
  	set_fdt_addr();
  
  	/* Ignore errors here; not all cases care about Ethernet addresses */
  	err = cboot_get_ethaddr(fdt, mac);
  	if (!err) {
  		void *blob = (void *)gd->fdt_blob;
  
  		err = fdtdec_set_ethernet_mac_address(blob, mac, sizeof(mac));
  		if (err < 0)
  			printf("failed to set MAC address %pM: %d\n", mac, err);
  	}
  
  	bootargs = cboot_get_bootargs(fdt);
  	if (bootargs) {
  		env_set("cbootargs", bootargs);
  		free(bootargs);
  	}
  
  	return 0;
  }
  